System for prevention and treatment of pressure ulcers

ABSTRACT

System for the prevention and treatment of pressure ulcers are described in which a portable support assembly may be worn by a bed-stricken individual around particular regions of the body where pressure ulcers tend to form. The portable support assembly may generally include one or more individual spring assemblies which are enclosed entirely within an inner fluid and/or outer fluid pad which extends over the entire assembly. Each of the spring assemblies may be secured to an outer shell which is relatively stiffer than the fluid layers.

FIELD OF THE INVENTION

This application is a continuation-in-part of U.S. application Ser. No.13/189,320 filed Jul. 22, 2011, which is incorporated herein byreference in its entirety.

FIELD OF THE INVENTION

The present invention relates to devices and methods for preventing andtreating pressure ulcers. More particularly, the present inventionrelates to devices and methods for preventing and treating pressureulcers with cushioning devices which are portable and easily conformedto various regions of the patient's body by utilizing individualcushioning pods which are supported within an inner fluid pad as well asan outer fluid pad.

BACKGROUND OF THE INVENTION

Individuals who are forced to sit or lie down for extended periods oftime typically experience tissue necrosis over localized regions oftheir body known as decubitus ulcers or pressure sores. These pressureulcers generally occur at locations of the body where the bonyprominence is high and the underlying skin breaks down when constantpressure is placed against the skin. Blood circulation is inhibited orprevented in these localized areas and can even occur when the patienthas been lying against or upon cushioning devices. Examples of areas ofthe body where pressure sores typically occur include the sacrum,greater trochanter, ischial tuberosity, malleolus, heel, etc. Whenpressure ulcers form, they can lead to extensive stays in the hospitalor even to amputation.

Conventional cushioning devices generally utilize flexible materialssuch as foam or springs which allow for the cushion to deform andconform to the patient's body. While the cushioning device attempts toredistribute the loading from localized regions of the patient's body toa larger area over the rest of the body, such devices typically bottomout such that the patient's body contacts the underlying platform andnonetheless localizes the pressure onto the body.

Other cushioning devices have utilized fluid-filled cushions whichconsist of large single bladders or compartmentalized fluid orgas-filled bladders which inhibit fluid contained within the bladdersfrom flowing laterally. Such fluid-filled cushions attempt to hammock orsuspend the patient's body while preventing the patient's body frombottoming out. However, such devices typically require a large area forplacement beneath the patient or require specialized bedding.

Yet other cushioning devices utilize segmented bladders in an attempt toisolate individual bladders from one another. Yet such segmentedcushions may fail to allow for the cushion to fully conform to thepatient's body as fluid between each of the segmented cushions isprevented.

Accordingly, there exists a need for a cushioning device which mayconform to regions of the patient's body to prevent decubitis ulcers ina manner which is more cost efficient, convenient, and effective.

BRIEF SUMMARY OF THE INVENTION

A portable support assembly may be worn by an individual who may bebed-stricken for an extended period of time to prevent the formation ofpressure ulcers. Such a portable support assembly may be worn by theindividual around particular regions of the body where pressure ulcerstend to form, e.g., sacrum, trochanter, ischium, as well as any otherregion of the body where support is desired. The portable supportassembly may be formed into an elongated shape to be wrapped entirelyaround the patient's body, e.g., around the hips or lower back, or aportion of the body, e.g., around the ankles or feet. Alternatively, thesupport assembly may be placed upon a bed or platform (or directlyintegrated into the bed or platform) upon which the patient is resting.

The support assembly may be configured to be portable such that it maybe worn directly over or upon the patient's body independently from theunderlying bed or cushion. Accordingly, the patient may utilize thesupport assembly on any underlying bed or platform. Additionally, whilethe examples described illustrate portable support assemblies, thesupport assembly may be integrated into a bed, underlying cushion,and/or mattress pad if so desired and as previously described.

Generally, the support assembly may comprise one or more pods positionedadjacent to one another, an inner pad enclosing the one or more podssuch that compression of the pods is controlled by the inner pad, anouter pad enclosing the inner pad, and an outer shell attached to theouter pad, wherein the outer shell is sufficiently flexible to be wornupon a portion of a subject's body.

In use, the support assembly may support the desired region of the bodyby securing a portable support assembly directly to the region of thebody to be supported, controlling displacement of one or more podspositioned along the support assembly beneath the region via an innerpad enclosing the one or more pods, and redistributing a pressure loadfrom the one or more pods and inner pad to an outer pad positioned alongthe support assembly and enclosing the inner pad, wherein theredistributed pressure load is exerted upon the body surrounding thesupported region.

One variation of the portable support assembly may generally define asecurement area for placement against the region of the body requiringsupport such as the sacrum. The securement area may generally comprise acentral portion with a first conformable portion and/or secondconformable portion extending from either side of the central portion.The first and/or second conformable portions may be flexible enough toallow for the portions to be wrapped around or about at least a portionof the patient's body such that the assembly may remain secured to thebody even when the patient moves about thereby maintaining the centralportion against the supported region of the body.

The central portion may provide the greatest amount of localized supportto the patient body by utilizing several fluid layers which arecontained one within another to receive the localized loading from theprotuberance from the patient's body and distribute the localized loadonto the surrounding areas and to further control displacement orinhibit or prevent the bottoming out of the fluid layers. The centralportion may thus contain one or more fluid filled individual pods whichmay be enclosed entirely within an inner fluid pad which envelopes theone or more pods within a secondary layer of fluid. The inner fluid padmay be localized along the central portion. Both the one or more podsand inner fluid pad are then enclosed entirely by a tertiary layer offluid within an outer fluid pad which may extend over the entireassembly. Each of the fluid layers may be secured to an outer shellwhich is relatively stiffer than the fluid layers and may restrict orlimit the expansion or movement of the fluid pods and/or fluid pads.While the assembly is adjustable to fit a particular patient, the outerpad, in particular, may optionally be filled with the fluid to avariable amount to further ensure that the assembly may be fitted orconformed to the anatomy of a particular patient.

Each of the one or more pods may be separated from one another such thatno fluid communication occurs between the pods and/or with the innerpad. Similarly, the inner pad may be separate from the outer pad suchthat no fluid communication occurs between the two. In other variations,some fluid communication may occur between the inner pad and outer padso long as the inner pad constrains and prevents the over-compression ofthe one or more pods to control their displacement and inhibit theirbottoming out.

Each of the pods and/or fluid pads may be filled with an incompressiblefluid such as water, viscous oil, or some other biocompatible fluid. Yetin other variations, the pods and/or fluid pads may be filledalternatively with a gas such as air, nitrogen, etc. In yet additionalvariations, the one or more pods and/or fluid pads may be filled witheither a fluid or gas or a combination of both depending upon thedesired degree of cushioning and force distribution.

The one or more fluid pods may each occupy an envelope of, e.g., 1 cm×1cm×0.5 cm to about 3 cm×3 cm×3 cm, in an uncompressed state and they maybe formed into various shapes, e.g., spherical, cylindrical, cubical,etc. Moreover, each of the pods may be formed from various materialssuch as polyurethane, silicone, vinyl, nylon, polyethylene vinyl acetate(PEVA), etc. having a thickness ranging from, e.g., 0.1 mm to 5 mm.Although the figure illustrates four pods, the number of pods containedwithin the inner pad may range anywhere from, e.g., 1 to 30 or more,arranged either uniformly or arbitrarily within the inner pad.Additionally, while the pods may be unconstrained within the inner padsuch that they freely move relative to one another, the pods may besecured within the inner pad either to one another or to the inner paditself such that their relative movement is constrained.

In yet other variations, rather than utilizing pods having a fluidcontained within, one or more spring assemblies may be used to providethe cushioning support. These spring assemblies may utilize variousspring types such as leaf or compression springs or various other typesof biasing mechanisms.

In either case, the pods may transfer localized loads from the patientreceived by a few pods either to adjacent pods through the compressionand transfer of pressure to adjacent contacting pods or throughtransmission via the fluid in the inner pad and/or outer pad. The amountof compression of the pods themselves may be controlled by the inner padwhich envelopes the pods within a pad localized over the centralportion. The inner pad may function as a hammocking layer to constrainthe amount of displacement experienced by the individual pods butbecause the inner pad itself may be fluid filled, the inner pad mayfurther provide support to the patient's body while also restrictingcompression of the pods. The amount of compression experienced by theindividual pods may thus be controlled by the inner pad to rangeanywhere from, e.g., 0% to 90% (or 10% to 90%), of the uncompressedheight of the pods.

The inner pad may be sized into various configurations depending upon,e.g., the number of pods or the area of the body to be supported.Moreover, the inner pad may also be made from the same or similarmaterial as the pods, e.g., polyurethane, silicone, vinyl, nylon,polyethylene vinyl acetate (PEVA), etc. While the inner pad may befilled with a fluid (or gas or combination of both), as described above,the inner pad may alternatively be devoid of fluid and instead be usedto constrain the expansion of the individual pods. Thus, inner pad maybe optionally vented to allow for any trapped air to vent from betweenthe pods when the pods undergo compression.

While the one or more pods and inner pad may be concentratedparticularly around the region of the body to be supported, anadditional outer pad may enclose and surround the inner pad whichfurther encloses the one or more pods. The outer pad may be similarlyfilled with a fluid or gas (or combination of both), as described above,and may be enclosed by a layer of material either the same or similar tothe material of the inner pad and/or pods and further have a uniform orvariable thickness ranging from, e.g., 0.5 mm to 4 cm. The outer pad mayfurther constrict the compression of the inner pad which in turnconstricts the compression of the one or more pods while additionallyproviding cushioning support to the surrounding tissue or bodystructures. Moreover, the outer pad may further extend over the lengthof the entire assembly to provide cushioning support to the region ofthe body upon which the assembly is secured.

Further supporting the assembly is the outer shell which may function asa restricting support to control displacement and inhibit the furthercompression of the outer pad to prevent the patient's body frombottoming out. The outer shell may be formed on a single side of theassembly such that when the assembly is worn by the patient, the outershell may be positioned away from the skin of the patient such that theouter pad remains in contact with the patient. The outer shell may beaccordingly made to be relatively stiffer than the outer pad yet stillbe flexible enough for conforming over or around the patient's body.Accordingly, the outer shell may be made from materials includingplastics such as polypropylene, ABS, PVC, polyethylene, nylon, acrylic,polycarbonate, etc. The outer shell may also be fabricated from othermaterials such as polymers, carbon fiber, light weight metals,elastomeric materials, rubbers, etc. Depending upon the material used,the outside shell can have a thickness ranging from, e.g., 1 mm to 3 cm.

When the patient wears the support assembly, the one or more fluidfilled pods may thus support the body portion (such as the sacrum ortrochanter) and due to the weight of the patient, the one or more podsmay compress against one another by a limited amount. However, the oneor more pods may be inhibited from bottoming out due to the surroundinghammocking inner pad. The pressure on the body portion may thus bereduced and distributed/transferred to the surrounding fluid present inthe inner pad. Moreover, the presence of the surrounding outer pad mayfurther transmit and redistribute the induced pressure upwards towardsand against the surrounding body portions, such as the thigh area. Thisdecrease in pressure can lead to a reduction in pressure against thelocalized body region to a value of less than or approximately 4.3 kPaand hence prevent tissue necrosis and reduce the occurrence of pressureulcers.

In yet another variation, an assembly may further incorporate additionallocalized support regions along different portions of the assembly.Other variations of the assembly may incorporate baffles and othermechanisms to optionally create interconnected fluid regions. Theseregions may allow for reducing the amount of fluid in the entire systemand prevent the fluid from pooling in one area.

In yet another variation, open cell foam may be placed between theindividual inner and outer fluid layers. This foam layer may besaturated with fluid and allow for the transfer of fluid pressurebetween the different fluid layers.

Additional variations may incorporate a breathable layer covering atleast a portion of the outer pad. The layer may be porous and can bemade from materials such as cotton, etc., such that air may circulatethrough the pores or openings.

In yet other variations, one or more vibrating elements may be attachedor integrated into the assembly, e.g., along the outer layer of theouter pad. These vibrating elements may vibrate to impart micro or macrovibrations directly against the contacted skin surface to relievepressure over the contact area or into the fluid pad itself toindirectly vibrate against the skin surface. The vibrating elements maygenerate micro-vibrations on the order of about, e.g., 10 to 500microns, in amplitude with a frequency ranging from about, e.g., 10 Hzto 300 Hz. These vibrations may allow for increased blood circulationand may also help decrease the incidence of pressure ulcers. Moreover,the vibrating elements may be comprised of piezoelectric, nitinol, orany other actuator driven elements.

In yet other variations, any of the embodiments described herein mayincorporate various temperature control mechanisms. These may includeone or more regions within the support pad assemblies which may becooled and/or heated to prevent and/or treat pressure ulcers.

With any of the variations described herein, different features andaspects from each of the variations may be combined with one another invarious combinations.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A shows a portion of a patient's body and the resultant inducedpressure imparted on portions of the body such as the trochanter.

FIG. 1B shows a portion of the patient's body with a portable supportassembly worn upon the body, e.g., around the hips, to alleviatepressure.

FIG. 2 shows a cross-sectional end view of one variation of a portablesupport assembly illustrating the various layered fluid pads containedwithin.

FIG. 3 shows a cross-sectional end view of another variation of thesupport assembly illustrating additional fluid pads contained within.

FIGS. 4A and 4B show perspective views of another variation of thesupport assembly which may be layered upon a hinged platform.

FIG. 5 shows a perspective view of yet another variation of the supportassembly incorporating features such as a cooling mechanism and/or aplurality of vibrating elements.

FIGS. 6A and 6B show perspective and side views of another variation ofthe support assembly which utilizes one or more spring assemblies incombination with the inner and/or outer pad.

FIG. 7 shows a perspective view of one variation of a spring assembly.

FIG. 8 shows a perspective view of another variation of a springassembly.

FIGS. 9A to 9D show various spring designs which may be used with any ofthe spring assemblies.

FIG. 10 shows a perspective view of another variation of the support padassembly having one or more temperature control regions.

FIG. 11 shows a perspective view of another variation of the support padassembly having a single temperature control region.

FIG. 12 shows a perspective view of another variation of a support padconfigured for alternative uses such as with a wheelchair.

FIG. 13 shows a perspective view of yet another variation of a supportpad configured for other regions of the body such as an elbow.

DETAILED DESCRIPTION OF THE INVENTION

Generally, in a healthy individual, the presence of muscle mass and softtissue ST usually functions to distribute and relieve pressure from bonyprotuberances of the body contacted against the underlying surface.However, when a patient PA is forced to lie on one portion of their bodyfor extended periods of time, areas such as the sacrum SA or trochanterTR may compress a region of the skin SK and tissue 12 between theprotuberance and a contact region 10 formed against the underlyingsurface, as shown in FIG. 1A.

Typical pressures generated in the hip area for healthy individualslying against a surface may range around 4 kPa. However, for olderand/or diseased individuals, the contact pressures between regions ofbony prominence and the skin is generally higher due to various factorssuch as muscle atrophy. For instance, increased pressures were found torange around 7.3 kPa. Blood circulation become restricted and tissuenecrosis typically begins when pressures range above 4.3 kPa leading tothe development of pressure ulcers.

Generally, a portable support assembly 14 may be worn by an individualwho may be bed-stricken for an extended period of time to prevent theformation of pressure ulcers. Such a portable support assembly 14 may beworn by the individual around particular regions of the body wherepressure ulcers tend to form, e.g., sacrum SA, trochanter TR, ischium,as well as any other region of the body where support is desired. Theportable support assembly 14 may be formed into an elongated shape to bewrapped entirely around the patient's body, e.g., around the hips orlower back, or a portion of the body, e.g., around the ankles or feet.Thus, although the example shown in FIG. 1B illustrates the assembly 14placed around the trochanter TR or sacrum SA, other embodiments mayinclude various shapes of the assembly 14 which may be sized forparticular body regions and are intended to be within the scope of thisdisclosure.

Moreover, the support assembly 14 is configured to be portable such thatit may be worn directly over or upon the patient's body independentlyfrom the underlying bed or cushion. Accordingly, the patient may utilizethe support assembly 14 on any underlying bed or platform. Additionally,while the examples described illustrate portable support assemblies, thesupport assembly may be integrated into a bed, underlying cushion,and/or mattress pad if so desired.

One variation of the portable support assembly 14 is illustrated in thecross-sectional view of FIG. 2, which illustrates a wearable hip-supportsystem. In this variation, the support assembly 14 may generally definea securement area 16 for placement against the region of the bodyrequiring support such as the sacrum SA. The securement area 16 maygenerally comprise a central portion 20 with first conformable portion18A and/or second conformable portion 18B extending from either side ofthe central portion 20. The first and/or second conformable portions18A, 18B may be flexible enough to allow for the portions 18A, 18B to bewrapped around or about at least a portion of the patient's body suchthat the assembly 14 may remain secured to the body even when thepatient moves about thereby maintaining the central portion 20 againstthe supported region of the body.

The central portion 20 may provide the greatest amount of localizedsupport to the patient body by utilizing several fluid layers which arecontained one within another to receive the localized loading from theprotuberance from the patient's body and distribute the localized loadonto the surrounding areas and to further control their displacement andinhibit or prevent the bottoming out of the fluid layers. The centralportion 20 may thus contain one or more fluid filled individual pods 28which may be enclosed entirely within an inner pad 24 which envelopesthe one or more pods 28 within a secondary layer of fluid. The inner pad24 may be localized along the central portion 20. The inner pad 24 maybe filled with a fluid (or gas) or optionally be devoid of any fluid, asdescribed in further detail below. Both the one or more pods 28 andinner pad 24 are then enclosed entirely by a tertiary layer of fluidwithin an outer pad 26 which may extend over the entire assembly 14.Each of the fluid layers may be secured to an outer shell 22 which isrelatively stiffer than the fluid layers and may restrict or limit theexpansion or movement of the fluid pods 28 and/or pads 24, 26. While theassembly 14 is adjustable to fit a particular patient, the outer pad 26,in particular, may optionally be filled with the fluid to a variableamount to further ensure that the assembly 14 may be fitted or conformedto the anatomy of a particular patient.

Each of the one or more pods 28 may be separated from one another suchthat no fluid communication occurs between the pods 28 and/or with theinner pad 24. Similarly, the inner pad 24 may be separate from the outerpad 26 such that no fluid communication occurs between the two. In othervariations, some fluid communication may occur between the inner pad 24and outer pad 26 so long as the inner pad 24 constrains and prevents theover-compression of the one or more pods 28 to control theirdisplacement and inhibit their bottoming out.

Each of the pods 28 and/or fluid pads 24, 26 may be filled with anincompressible fluid such as water, salt solution, viscous oil, or someother biocompatible fluid. Yet in other variations, the pods 28 and/orfluid pads 24, 26 may be filled alternatively with a gas such as air,nitrogen, etc. In yet additional variations, the one or more pods 28and/or fluid pads 24, 26 may be filled with either a fluid or gas or acombination of both depending upon the desired degree of cushioning andforce distribution.

The one or more fluid pods 28 may each occupy an envelope of, e.g., 1cm×1 cm×0.5 cm to about 3 cm×3 cm×3 cm, in an uncompressed state andthey may be formed into various shapes, e.g., spherical, cylindrical,cubical, etc. Moreover, each of the pods may be formed from variousmaterials such as polyurethane, silicone, vinyl, nylon, polyethylenevinyl acetate (PEVA), etc. having a thickness ranging from, e.g., 0.1 mmto 5 mm. Although the figure illustrates four pods 28, the number ofpods 28 contained within the inner pad 24 may range anywhere from, e.g.,1 to 30 or more, arranged either uniformly or arbitrarily within theinner pad 24. Additionally, while the pods 28 may be unconstrainedwithin the inner pad 24 such that they freely move relative to oneanother, the pods 28 may be secured within the inner pad 24 either toone another or to the inner pad 24 itself such that their relativemovement is constrained.

In either case, the pods 28 may transfer localized loads from thepatient received by a few pods 28 either to adjacent pods through thecompression and transfer of pressure to adjacent contacting pods orthrough transmission via the fluid in the inner pad 24 and/or outer pad26. The amount of compression of the pods 28 themselves may becontrolled by the inner pad 24 which envelopes the pods 28 within a padlocalized over the central portion 20. The inner pad 24 may function asa hammocking layer to constrain the amount of displacement experiencedby the individual pods 28 but because the inner pad 24 itself may befluid filled, the inner pad 24 may further provide support to thepatient's body while also restricting compression of the pods 28. Theamount of compression experienced by the individual pods 28 may thus becontrolled by the inner pad 24 to range anywhere from, e.g., 0% to 90%(or 10% to 90%), of the uncompressed height of the pods 28. For example,for a pod 28 having an uncompressed height of 3 cm, the compression ofthe pod 28 may range anywhere from, e.g., 0 cm to 2.7 cm.

The inner pad 24 may be sized into various configurations dependingupon, e.g., the number of pods 28 or the area of the body to besupported. Moreover, the inner pad 24 may also be made from the same orsimilar material as the pods 28, e.g., polyurethane, silicone, vinyl,nylon, polyethylene vinyl acetate (PEVA), etc. While the inner pad 24may be filled with a fluid (or gas or combination of both), as describedabove, the inner pad 24 may alternatively be devoid of fluid and insteadbe used to constrain the expansion of the individual pods 28. Thus,inner pad 24 may be optionally vented to allow for any trapped air tovent from between the pods 28 when the pods 28 undergo compression.

While the one or more pods 28 and inner pad 24 may be concentratedparticularly around the region of the body to be supported, anadditional outer pad 26 may enclose and surround the inner pad 24 whichfurther encloses the one or more pods 28. The outer pad 26 may besimilarly filled with a fluid or gas (or combination of both), asdescribed above, and may be enclosed by a layer of material either thesame or similar to the material of the inner pad 24 and/or pods 28 andfurther have a uniform or variable thickness ranging from, e.g., 0.5 mmto 4 cm. The outer pad 26 may further constrict the compression of theinner pad 24 which in turn constricts the compression of the one or morepods 28 while additionally providing cushioning support to thesurrounding tissue or body structures. Moreover, the outer pad 26 mayfurther extend over the length of the entire assembly 14 to providecushioning support to the region of the body upon which the assembly 14is secured.

Additionally, while the outer pad 26 may have a thickness ranginganywhere from, e.g., 5 mm to 2 cm or more (such as in areas in contactagainst the sacrum), the inner pad 24, outer pad 26, and/or pods 28 maybe filled with a fluid having a density which is relatively higher thanthe density of a body. For example, the density of the human body isabout 1.01 g/cm² and a salt solution filled within any of the pads 24,26 and/or pods 28 can have density of, e.g., 1.03 to 1.1 g/cm². By usinga highly saturated salt solution used as the fluid, a further cushioningeffect may be achieved for providing comfort to the patient when theassembly is in use.

Further supporting the assembly is the outer shell 22 which may functionas a restricting support to control displacement and inhibit the furthercompression of the outer pad 26 to prevent the patient's body frombottoming out. The outer shell 22 may be formed on a single side of theassembly 14 such that when the assembly 14 is worn by the patient, theouter shell 22 may be positioned away from the skin of the patient suchthat the outer pad 26 remains in contact with the patient. The outershell 22 may be accordingly made to be relatively stiffer than the outerpad 26 yet still be flexible enough for conforming over or around thepatient's body. Accordingly, the outer shell 22 may be made frommaterials including plastics such as polypropylene, ABS, PVC,polyethylene, nylon, acrylic, polycarbonate, etc. The outer shell 22 mayalso be fabricated from other materials such as polymers, carbon fiber,light weight metals etc. Depending upon the material used, the outsideshell 22 can have a thickness ranging from, e.g., 1 mm to 3 cm.

When the patient wears the support assembly, the one or more fluidfilled pods 28 may thus support the body portion (such as the sacrum SAor trochanter TR) and due to the weight of the patient, the one or morepods 28 may compress against one another by a limited amount. However,the one or more pods 28 may be inhibited from bottoming out due to thesurrounding hammocking inner pad 24. The pressure on the body portionmay thus be reduced and distributed/transferred to the surrounding fluidpresent in the inner pad 24. Moreover, the presence of the surroundingouter pad 26 may further transmit and redistribute the induced pressureupwards towards and against the surrounding body portions, such as thethigh area. This decrease in pressure can lead to a reduction inpressure against the localized body region to a value of less than orapproximately 4.3 kPa and hence prevent tissue necrosis and reduce theoccurrence of pressure ulcers.

In another variation, the one or more pods 28 may be connected directlyto the outer shell 22 and contained by the hammocking inner pad layer 24which prevents the pods 28 from bottoming out, as described above. Theouter fluid pad 26 may be laid atop the one or more pods 28 andhammocking inner layer 24. Alternatively, the one or more pods 28(contained within the hammocking inner layer 24) may come into directcontact against the patient and the outer fluid pad 26 may instead beattached directly to the outer shell 22.

In yet another variation, FIG. 3 shows a cross-sectional view of anassembly which is similarly constructed to the variation of FIG. 2 butwhich may further incorporate additional localized support regions. Forinstance, in the variation shown, a first fluid inner pad 30A having oneor more pods 32A contained within may be integrated along the firstconformable portion 18A extending from the central portion 20.Similarly, a second fluid inner pad 30B having one or more pods 32Bcontained within may be integrated along the second conformable portion18B extending from the opposite side of the central portion 20. In thisvariation, the conformable portions 18A, 18B may be wrapped or securedagainst the hips of the patient such that the corresponding inner pads30A, 30B are positioned over either or both trochanters TR of thepatient while the central portion 20 is positioned over the sacrum SA toprovide support around the entire hip and lower back regions of thepatient. As described herein, the number and size of the pods 32A, 32Bmay be varied.

While the support assembly 14 may be sized in various configurationsdepending upon the region of the body to which the assembly is to bepositioned, another example of an assembly configuration is shown in theperspective views of FIGS. 4A and 4B. In this example, the supportsystem may be configured as a hinged fluid pad assembly 40 having acentral portion 42 and a first foldable portion 44A and a secondfoldable portion 44B extending from either side of the central portion42. The outer shell of the foldable portions 44A, 44B may be coupled viacorresponding first hinged region 46A and second hinged region 46B suchthat the assembly 40 may be laid flat upon a bed or platform. The innerfluid pad 24 and one or more pods 28 may be positioned upon the centralportion 42 and/or optionally along the first and/or second foldableportions 44A, 44B as well while the outer pad 26 may extend continuouslyalong the length of the entire assembly 40. In use, the assembly 40 maybe laid flat and folded over upon or against the patient's body andsecured accordingly.

Other variations of the assembly may incorporate baffles and othermechanisms to optionally create interconnected fluid regions. Theseregions may allow for reducing the amount of fluid in the entire systemand prevent the fluid from pooling in one area.

In yet another variation, open cell foam may be placed between theindividual inner and outer fluid layers. This foam layer may besaturated with fluid and allow for the transfer of fluid pressurebetween the different fluid layers.

FIG. 5 shows a perspective view of yet another variation in which thesupport assembly 50 may incorporate a breathable layer covering at leasta portion of the outer pad 26. The layer may be porous and can be madefrom materials such as cotton, etc., such that air may circulate throughthe pores or openings 52. A pump 54 coupled via a fluid line 56 may beoptionally attached to the assembly 50 to pump air through the pores oropenings 52.

In yet other variations, one or more vibrating elements 58 may beattached or integrated into the assembly 50, e.g., along the outer layerof the outer pad 26. These vibrating elements 58 may vibrate to impartmicro or macro vibrations directly against the contacted skin surface torelieve pressure over the contact area or into the fluid pad itself toindirectly vibrate against the skin surface. The vibrating elements 58may generate micro-vibrations on the order of about, e.g., 10 to 500microns, in amplitude with a frequency ranging from about, e.g., 10 Hzto 300 Hz. These vibrations may allow for increased blood circulationand may also help decrease the incidence of pressure ulcers. Moreover,the vibrating elements 58 may be comprised of piezoelectric, nitinol, orany other actuator driven elements.

In other variations, the assembly 50 may be integrated with an optionalmattress topper 54 to provide stability to the assembly 50 whenpositioned against the patient.

In yet another variation, the support assembly may utilize one or morespring assemblies in combination with the inner pad 24 and/or outer pad26 rather than using the one or more pods 28. An example is shown in theperspective view of FIG. 6A which shows a variation of the assembly withouter pad 26 positioned atop one or more spring assemblies 60 ratherthan one or more pods. FIG. 6B shows a partial cross-sectional side viewof one or more spring assemblies 60 secured upon the outer shell 22 andthe outer pad 26 positioned atop the spring assemblies 60. The number ofindividual compression assemblies 60 in the array can vary, e.g., from 1to 25 or more depending upon the desired treatment area. Moreover, eachof the individual spring assemblies 60 is designed to be non-bottomingand further designed to reduce the pressure to less than or equal to,e.g., 32 mm of Hg, when a person uses the system.

One variation of a spring assembly may have an individual base 62 forsecurement to the outer shell 22 and a corresponding top layer 66 forcontacting against the outer pad 26 and/or directly against the patientbody. Between the top layer 66 and base 62 are one or more biasingmembers 64, e.g., spring elements. An example is shown in theperspective view of FIG. 7 which illustrates the top layer 66 and base62 formed in a circular configuration although they may be formed in anynumber of shapes which are suitable for placement between the shell 22and outer pad 26. The variation of biasing members 64 shown may comprisesuperelastic shape memory alloys such as heat-formed Nitinol formed,e.g., into flattened strips of material which are configured into leafor compression springs, as shown. When a force is applied to the toplayer 66, such as by the patient body, the biasing members 64 compressand their height decreases in response to the application of the forcecausing the top layer 66 to move towards the base 62.

The spring assembly shown in FIG. 7 is illustrated as having fourbiasing members 64 but the assembly can have one, two, three, or morebiasing members 64. The biasing members 64 can also be made from othermaterials such as stainless steels, plastics, elastomers, and othersuitable materials.

FIG. 8 shows an alternative variation of a spring assembly having a base70 and a top layer 72 with the biasing members 74 as previouslydescribed. The assembly may further have one or more post members 76extending from the base 70 for translational engagement with one or morecorresponding guide members 78 which may be aligned to receive the postmembers 76. The post members 76 may prevent the top layer 72 fromrotating out of alignment with respect to base 70 during use. Moreover,the biasing members 74 may be designed to be a multiple prong anchor orflower design although any of the spring designs described herein may beused.

The individual spring assembly can have a surface area, e.g., from 0.5to 1.0 cm² or even up to 200 cm², and an uncompressed height rangingfrom, e.g., 1 cm to 3 cm. The biasing members 64 can also vary fromhaving a constant force to having compression systems with a singlespring constant or multiple spring constants.

Moreover, various other biasing elements such as extension springs, leafsprings, torsion springs, or any formed or shaped design which canaccomplish similar functions may be used. Aside from the design, thedifferent kinds of springs and compression pods may be designed to havespring constants either independently or on a system level such that thedisplacement or travel to support the patient does not result inpressures greater than, e.g., 4.3 kPA or similar pressures, which cancause tissue necrosis and lead to formation of pressure ulcers.

Other examples of various spring designs which may be used with any ofthe assemblies described herein are shown in FIGS. 9A to 9D. Forinstance, FIG. 9A shows a side view of a leaf spring 80 while FIGS. 9Band 9C show side views of a conical spring 82 and a cylindrical spring84, respectively, which may be used as well. FIG. 9D shows a perspectiveview of an elastomeric spring 86 which may also be used, if so desired.

Experiment

Tests using exemplary embodiments of the support assembly describedherein have been conducted utilizing an array of individual fluid podsenclosed within an inner enveloping pad. This assembly was thenenveloped within an outer fluid pad where both the fluid pods and outerpads were filled with water. The assembly was positioned near asimulated sacrum region and a similar arrangement was positioned near asimulated trocanter region.

An artificial male hip model was used to which a 0 to 20 lb FLEXIFORCE®(Tekscan, Inc., MA) sensor was attached to the sacrum region of the hipmodel. The FLEXIFORCE® sensor was used to sense contact force/pressureand an 8 lb load (ball) was used as the simulated load of a patient.

A first test had the hip model placed on a simulated mattress having afoam pillow with a thickness of about 1 cm. The hip model was thenloaded three times with the 8 lb load and a corresponding force readingwas recorded. A second test was then conducted where the hip model wasplaced on the support assembly pad and was then loaded with the 8 lbload. The hip model was then loaded again three times with the 8 lb loadand a corresponding force reading was recorded. The tabulated resultsare shown in the following table:

TABLE 1 Force measurements results from simulated loading.Force/Pressure Test Force in N Force in N (decrease by support No(simulated mattress) (support assembly pad) assembly pad) 1 7.70 4.2944% 2 6.33 3.42 46% 3 5.65 3.42 39%

Accordingly, use of the support assembly pad yielded an averagereduction of 43% in measured pressure as experienced by the sacrum.

Temperature Control

Additionally and/or alternatively, any of the variations describedherein may also incorporate the use of temperature modulation andcontrol to further help prevent the formation of pressure ulcers. Forexample, the support assembly pad may be controlled to have atemperature which is lower than body temperature to help prevent theformation of pressure ulcers while having an assembly pad controlled tohave a temperature which is higher than body temperature can be used totreat pressure ulcers which have already formed upon the body. Forexample, the assembly pad can be configured to control the contactedskin/tissue temperature to within ±10° C. of body temperature.

In addition to unidirectional temperature control (either heating orcooling) bidirectional temperature control can be achieved (selectivelyor alternatively heating and/or cooling). This allows the same assemblypad to be used for prevention and treatment of pressure ulcers.Temperature control can be achieved using any of several various methodsand mechanisms. One example is shown in the perspective view of FIG. 10which illustrates an assembly pad having several individual temperatureregions 92A, 92B, 92C, 92D which may be controlled individually orsimultaneously to heat or cool specified regions of the pad assembly.Each of the temperature regions may be in electrical communication witha controller 90, e.g., processor, which may be integrated with the padassembly or arranged as a separate mechanism. FIG. 11 shows anothervariation where single temperature region 94 may be integrated over thepad assembly to heat or cool the entire pad assembly in contact with thepatient.

The unidirectional or bidirectional temperature control may utilize anynumber of temperature altering mechanisms. For example, thermoelectriccooling and heating elements (e.g., Peltier junctions) may be used orresistive heating and cooling elements may be used. Alternatively,inductive heating and cooling elements may also be used. Additionallyand/or alternatively, chemically cooling and/or heating reactingmaterials (e.g., exothermic and/or endothermic) may be used as the fluidfilling the one or more pods and/or pads. In yet another alternative, acooling or heating fluid may be pumped in a circulating manner with anexternally located cooling and/or heating mechanisms in fluidcommunication with a pumping mechanism.

In yet other variations, the pad assembly may be designed foralternative uses. For example, the pad may be configured for use by apatient sitting in a wheelchair, standard chair, or other sitting,standing or sleeping devices or platforms. An example of a simplifiedpad assembly 100 is shown in the perspective view of FIG. 12.Alternatively, a pad assembly 110 shown in FIG. 13 may be configured forresting, e.g., during surgery, beneath an extremity such as an elbow orany other portion of the body which may come into contact against a hardsurface for an extended period of time. The configured pad 110 maycushion, e.g., the ulnar nerve and may include a flat pad with a singlefluid pod, for instance.

The applications of the devices and methods discussed above are notlimited to particular regions of the body such as the sacrum,trochanter, heel, etc. but may include any number of furtherapplications. Modification of the above-described device and methods forcarrying out the invention, and variations of aspects of the inventionthat are obvious to those of skill in the art are intended to be withinthe scope of the claims.

What is claimed is:
 1. A support assembly, comprising: an outer supportwhich is sufficiently flexible to be placed upon a portion of asubject's body; one or more spring assemblies positioned adjacent to oneanother upon an inner surface of the outer support; and, a fluid filledouter pad positioned upon the one or more spring assemblies and theinner surface of the outer support such that side portions of the outerpad away from the one or more spring assemblies are adjustablypositionable against the subject's body and the outer support ismaintained at a distance from the subject's body.
 2. The assembly ofclaim 1 wherein the one or more spring assemblies each comprise one ormore biasing elements compressible between the outer support and outerpad.
 3. The assembly of claim 2 wherein the spring assemblies eachcomprise a base and a top layer between which the one or more biasingelements are attached.
 4. The assembly of claim further comprising oneor more temperature controlled regions within the support assembly. 5.The assembly of claim 4 wherein the one or more temperature controlledregions are configured to increase and/or decrease in temperaturerelative to a temperature of subject's body.
 6. The assembly of claim 1further comprising an inner pad enclosing the one or more springassemblies.
 7. The assembly of claim 1 wherein the support assembly isconfigured to be worn in proximity to a sacrum.
 8. The assembly of claim1 further comprising an outer covering over the outer pad which definesone or more openings through the outer covering.
 9. A support assembly,comprising: an outer support positionable beneath a portion of asubject's body; one or more spring assemblies positioned adjacent to oneanother upon a first surface of the outer support; an inner padenclosing the one or more spring assemblies; and, a fluid filled outerpad positioned upon the inner pad and the first surface of the outersupport such that side portions of the outer pad away from the one ormore spring assemblies are adjustably positionable against the subject'sbody and the outer support is maintained at a distance from thesubject's body.
 10. The assembly of claim 9 wherein the one or morespring assemblies each comprise one or more biasing elementscompressible between the outer support and outer pad.
 11. The assemblyof claim 10 wherein the spring assemblies each comprise a base and a toplayer between which the one or more biasing elements are attached. 12.The assembly of claim 9 further comprising one or more temperaturecontrolled regions within the support assembly.
 13. The assembly ofclaim 12 wherein the one or more temperature controlled regions areconfigured to increase and/or decrease in temperature relative to atemperature of subject's body.
 14. The assembly of claim 9 wherein thesupport assembly is configured to be worn in proximity to a sacrum. 15.The assembly of claim 9 further comprising an outer covering over theouter pad which defines one or more openings through the outer covering.16. A method of supporting a region of a body, comprising: positioning aportable support assembly having a flexible outer support in proximityto the region of the body to be supported; controlling displacement ofone or more spring assemblies positioned along the support assemblybeneath the region of the body; and redistributing a pressure load fromthe one or more spring assemblies to a fluid filled outer pad positionedalong the support assembly and upon the one or more spring assembliessuch that side portions of the outer pad away from the one or morespring assemblies are adjustably positionable against the body and wherethe outer support is maintained at a distance from the body, wherein theredistributed pressure load is exerted upon the body surrounding thesupported region.
 17. The method of claim 16 wherein positioningcomprises wrapping the portable support assembly upon the region of thebody via the flexible outer support.
 18. The method of claim 16 whereincontrolling displacement comprises constraining compression of the oneor more spring assemblies via an inner pad enclosing the one or morespring assemblies while further supporting the region of the body viathe inner pad.
 19. The method of claim 16 wherein redistributingcomprises transferring the pressure load from the inner pad to the outerpad via pressure transmission through fluid contained within the innerpad.
 20. The method of claim 16 further comprising constrainingcompression of the one or more spring assemblies via an outer support.21. The method of claim 16 further comprising controlling a temperatureof one or more regions of the body via the support assembly.